Boosting Piezo‐Catalytic Activity of KNN‐Based Materials with Phase Boundary and Defect Engineering

Abstract

Although the piezo‐catalysis is promising for the environmental remediation and biomedicine, the piezo‐catalytic properties of various piezoelectric materials are limited by low carrier concentrations and mobility, and rapid electron‐hole pair recombination, and reported regulating strategies are quite complex and difficult. Herein, a new and simple strategy, integrating phase boundary engineering and defect engineering, to boost the piezo‐catalytic activity of potassium sodium niobate ((K, Na)NbO3, KNN) based materials is innovatively proposed. Tur strategy is validated by exampling 0.96(K0.48Na0.52)Nb0.955Sb0.045O3‐0.04(BixNa4‐3x)0.5ZrO3‐0.3%Fe2O3 material having phase boundary engineering and conducted the defect engineering via the high‐energy sand‐grinding. A high reaction rate constant k of 92.49 × 10−3 min−1 in the sand‐grinding sample is obtained, which is 2.40 times than that of non‐sand‐grinding one and superior to those of other representative lead‐free perovskite piezoelectric materials. Meanwhile, the sand‐grinding sample has remarkable bactericidal properties against Escherichia coli and Staphylococcus aureus. Superior piezo‐catalytic activities originate from the enhanced electron‐hole pair separation and the increased carrier concentration. This study provides a novel method for improving the piezo‐catalytic activities of lead‐free piezoelectric materials and holds great promise for harnessing natural energy and disease treatment.

Poling‐induced enhancement of piezocatalytic performance of 0.96K0.5Na0.5NbO3‐0.04Bi0.5Na0.5ZrO3 ceramic blocks

“…where C, C 0 , and k are the concentration at the ultrasonic time of t, the initial concentration of the dye solution, and the reaction rate constant, respectively. 30 Compared with unpoled samples, the k values of the poled samples are all improved, and the maximum of k values reaches 14.70 × 10 −3 min −1 , which is 3.44 times more than that of unpoled ceramics. Correspondingly, the crystal structures of both the primordial and activated poled samples show similar characteristics of diffraction peaks in Figure 4D.…”

“…13 Thus poled samples are more likely to react with cationic RhB and MB molecules, while the reaction with anionic Ab10B species is poor. Generally, the piezocatalytic activities obey the Langmuir-Hinshelwood model, as shown in Equation (3) 30 :…”

Boosting Piezocatalytic Activity of Bi5Ti3FeO15/BiOCl Heterostructured Nanocomposites for Degrading Multiple Dyes and Antibiotics

“…In the past decade, many piezoelectric materials have been demonstrated as promising catalysts in environmental remediation, and significant progress has been achieved. − However, the catalytic efficiencies of the currently reported piezocatalysts need to be further improved to meet the demands of practical applications. The development of high-performance piezocatalysts is one of the key concerns in the piezocatalytic area.…”